Method of fabricating a miniature device having an acoustic diaphragm

ABSTRACT

A method of forming a device having a compliant member includes applying heat to a thermoplastic elastomer to maintain the thermoplastic elastomer in a softened state. The thermoplastic elastomer is extruded in the softened state as a film of thermoplastic elastomer. One or more of a bobbin and a housing, each having and end, is positioned such that the end extends at least partially into the film of thermoplastic elastomer. The positioning occurs when the thermoplastic elastomer is in the softened state and/or the bobbin and/or housing is at a temperature that is greater than a temperature of the film of thermoplastic elastomer. The film is cooled so that the bobbin and/or housing are secured to the film and so that the thermoplastic elastomer is in a state that exhibits rubber-like properties.

BACKGROUND

This disclosure relates to a miniature device having a compliant member.More particularly, the disclosure relates to a method of fabricating anacoustic diaphragm on the miniature device.

SUMMARY

In one aspect, a method of fabricating a device having a complaintmember includes applying heat to a thermoplastic elastomer to maintainthe thermoplastic elastomer in a softened state. The thermoplasticelastomer is extruded in the softened state into a film of thermoplasticelastomer. One or more of a bobbin and a housing, each having and end,are positioned such that the end of the bobbin and/or housing extends atleast partially into the film of thermoplastic elastomer. Thepositioning occurs when the thermoplastic elastomer is in the softenedstate and/or the bobbin and/or housing is at a temperature that isgreater than a temperature of the film of thermoplastic elastomer. Thefilm of thermoplastic elastomer having the bobbin positioned therein iscooled so that the bobbin and/or housing are thereby secured to the filmof thermoplastic elastomer.

Examples may include one or more of the following features:

Extruding the thermoplastic elastomer may include extruding thethermoplastic elastomer as a film on a release liner. The release linermay be removed from the film of thermoplastic elastomer subsequent tothe cooling of the film of thermoplastic elastomer.

The film of thermoplastic elastomer may be cooled into a rubber stateand heat may be applied to the film of thermoplastic elastomer in therubber state to change the film of thermoplastic elastomer into thesoftened state prior to the positioning of the housing.

The temperature of the film of thermoplastic elastomer may be at anambient temperature when the housing is at a temperature that is greaterthan the temperature of the film of thermoplastic elastomer.

A portion of the film of thermoplastic elastomer that extends outside adiameter of the housing may be removed after cooling the film ofthermoplastic elastomer.

The thermoplastic elastomer may include a thermoplastic vulcanizate.Applying heat to the thermoplastic vulcanizate to maintain thethermoplastic vulcanizate in a softened state may include heating thethermoplastic vulcanizate to greater than a crystalline meltingtemperature of a polypropylene component. The thermoplastic elastomermay include a styrenic-based thermoplastic elastomer. Applying heat tothe styrenic-based thermoplastic elastomer to maintain thestyrenic-based thermoplastic elastomer in a softened state may includeheating the styrenic-based thermoplastic elastomer to greater than aglass transition temperature of a styrenic component. The thermoplasticelastomer may have a hardness of less than 15 Shore A. The thermoplasticelastomer may have a Young's modulus of less than 0.25 megapascals.

Positioning one or more of a bobbin and a housing may includepositioning the bobbin and the housing such that the bobbin is insidethe housing and concentric with the housing. The bobbin and/or thehousing may be at a temperature that is in a range from about 100° C. toabout 200° C. during the positioning of the bobbin and/or the housing.

In accordance with another aspect, a device includes a compliant memberand a housing. The compliant member has a substantially planar shape andformed of a film of a thermoplastic elastomer. The housing has an endthat extends at least partially into the compliant member. Thethermoplastic elastomer adheres to a portion of the housing at the endof the housing to form a meniscus having a height defined along a wallof the housing.

Examples may include one or more of the following features:

The compliant member may include a meniscus formed at each of an innerwall surface of the housing and an outer wall surface of the housing.

The device may further include a bobbin disposed inside the housing andhaving an end that extends at least partially into the compliant member.The thermoplastic elastomer adheres to a portion of the bobbin at theend of the bobbin to form a meniscus having a height defined along awall of the bobbin. The compliant member may further include a meniscusformed at each of an inner wall surface of the housing, an outer wallsurface of the housing, an inner wall surface of the bobbin and an outerwall surface of the bobbin.

The housing may be a tube having an opening at the end.

The thermoplastic elastomer may include a thermoplastic vulcanizate or astyrenic-based thermoplastic elastomer. The thermoplastic elastomer mayhave a hardness of less than 15 Shore A. The thermoplastic elastomer mayhave a Young's modulus of less than 0.25 megapascals.

In accordance with another aspect, a microspeaker device includes anacoustic diaphragm, a housing, a bobbin and a coil. The acousticdiaphragm has a substantially planar shape and formed of a film ofthermoplastic elastomer. The housing has an end extending at leastpartially into the film of thermoplastic elastomer. The film adheres toa portion of the housing at the end of the housing to form a firstmeniscus along a portion of a wall of the housing. The bobbin has abobbin surface and is disposed inside the housing. The bobbin has an endextending at least partially into the film of thermoplastic elastomer.The film adheres to a portion of the bobbin at the end of the bobbin toform a second meniscus along a wall of the bobbin. The coil is wound onthe bobbin surface.

Examples may include one or more of the following:

An axis of the housing and an axis of the bobbin may be colinear.

The first meniscus may include a first inner meniscus having a heightalong an inner wall surface of the housing and a first outer meniscushaving a height along an outer wall surface of the housing, and thesecond meniscus may include a second inner meniscus having a heightalong an inner wall surface of the bobbin and a second outer meniscushaving a height along an outer wall surface of the bobbin.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and further advantages of examples of the present inventiveconcepts may be better understood by referring to the followingdescription in conjunction with the accompanying drawings, in which likenumerals indicate like structural elements and features in variousfigures. The drawings are not necessarily to scale, emphasis insteadbeing placed upon illustrating the principles of features andimplementations.

FIG. 1A, FIG. 1B and FIG. 1C are a perspective illustration, aperspective cutaway illustration and an exploded cutaway illustration,respectively, of an example of a microspeaker for a miniature earbud.

FIG. 2 is a flowchart representation of an example of a method 100 offabricating a device having a compliant member.

FIG. 3A is a cross-sectional side view of an example of a thermoplasticelastomer film on a release liner.

FIG. 3B shows end portions of a housing and a bobbin extending into athermoplastic elastomer film.

FIG. 3C shows the thermoplastic elastomer film of FIG. 4B that remainsas a substantially planar compliant member after the release liner isremoved.

FIG. 4 is a graphical representation of how the storage modulus of anexample of a thermoplastic elastomer material varies as a function oftemperature.

FIG. 5 shows a magnified cross-sectional view of a portion of the endsof the housing and bobbin corresponding to the left side of FIG. 3C.

FIG. 6 is a flowchart representation of another example of a method offabricating a device having a compliant member.

FIG. 7 is a flowchart representation of another example of a method offabricating a device having a compliant member.

DETAILED DESCRIPTION

Modern in-ear headphones, or earbuds, typically include microspeakers.The microspeaker may include a coil that is attached to an acousticdiaphragm either directly or through a bobbin on which the coil iswound. Motion of the diaphragm due to an electrical signal provided tothe coil results in generation of an acoustic signal that is responsiveto the electrical signal. The microspeaker typically includes a housing,such as a sleeve or tube, which encloses the bobbin, coil and a magneticstructure. As the size of the earbud decreases, it becomes increasinglydifficult to fabricate the acoustic diaphragm with an elastic suspensionat one end of the bobbin (or coil) and housing.

FIG. 1A, FIG. 1B and FIG. 1C are a perspective illustration, aperspective cutaway illustration and an exploded cutaway illustration,respectively, of an example of a microspeaker 10 that can be used in aminiature earbud. The microspeaker 10 includes a cylindrical housing 12having an opening at both ends. Inside the housing 12 is a bobbin 14that is nominally cylindrical in shape and which is open at least at oneend. The housing 12 and bobbin 14 are secured at one of their ends to acompliant member 16. In some examples, the housing 12 is made ofstainless steel and the bobbin 14 is made of a polyimide (e.g., KAPTON)or polyethylene terephthalate (PET) (e.g., MYLAR®). A magnet assembly 18is secured to a platform 19 at an end of the housing 12 that is oppositeto the compliant member 16. The magnet assembly 18 includes two magnetpieces 18A and 18B separated by a coin 18C. The magnet assembly 18extends along an axis 20 of the housing 12 and into an open regioninside the bobbin 14. In one example, the magnet pieces 18A and 18B arecylindrical neodymium magnets. A coil 22 is wound onto an outsidesurface of the bobbin 14. The bobbin 14 has an axis that is colinearwith the housing axis 20. The bobbin 14 moves substantially along thehousing axis 20 in response to an electrical current conducted throughthe coil 22. In turn, a central circular portion of the compliant member16 moves axially and displaces air to thereby create an acoustic signal.

In one technique for fabricating a compliant member, an open end of ahousing and an open end of a bobbin are placed into a single thin layerof liquid silicone rubber. The liquid silicone rubber is then cured toform the compliant member. The central region of the compliant memberthat is located within the end region of the bobbin can be stiffenedwhile the annular region that surrounds the central region remainscompliant. Difficulties arise with this technique as the liquid siliconehas a surface tension that causes the liquid to adhere to and “climb up”the walls of the housing and the bobbin to form menisci. The migrationof the liquid silicone along the walls can occur quickly, for example,within a few seconds of placing the ends of the housing and bobbin intothe liquid silicone rubber. The result of the migration is a reductionin the thickness of the cured layer of silicone which can lead to holesin the compliant member. Holes can form during the demolding processbecause the compliant member is weakened at the thinned areas. Inaddition, thinned areas may result in holes being formed in thecompliant member or tearing of the compliant member during operation ofthe microspeaker.

One method for fabricating the compliant member is described in U.S.patent application Ser. No. 15/182,069, filed Jun. 14, 2016, thedisclosure of which is incorporated herein by reference in its entirety.According to the method, which is based on a two-pass silicone filmcasting process, a second elastomeric layer is applied to a thicker andat least partially cured first elastomeric layer. This method results ina reduction of the thinning of the full elastomeric layer. Acorresponding reduction in the formation of holes during demolding andtearing during microspeaker operation is achieved.

According to another method for fabricating the compliant member, asdescribed in U.S. patent application Ser. No. 15/598,065, filed May 17,2017, the disclosure of which is incorporated herein by reference in itsentirety, a single pass elastomeric layer casting process is employed.In this method, the viscosity of the layer is controlled duringfabrication by appropriate application of heat or ultraviolet (UV) lightin a manner that limits the migration of the liquid silicone along thewalls of the housing and bobbin, and the height of the resulting menisciformed along the walls. Consequently, occurrences of hole formation andtearing may be further reduced.

The above referenced methods have associated challenges, including cost,complexity and material availability. For example, control of theviscosity of the elastomeric materials during the fabrication processesusing heat or UV light can be difficult. In addition, silicones or othersoft thermoset elastomers such as polyurethanes can be expensive and maynot be commercially available. Furthermore, various elastomericmaterials may have limited shelf-life (e.g., a few months); requiringrepurchase of the material while an unused portion of a prior purchaseamount may have expired. Moreover, the time needed to complete thefabrication process can be extensive. For example, the thermosetelastomeric material may require extended curing times (e.g., two hoursor more).

In examples described herein for a method of fabricating a device havinga compliant member, heat is applied to a thermoplastic elastomericmaterial to change the material to a softened state and/or maintain thematerial in a softened state. As used herein, a “softened state” meansthat the material is easily shaped through the application of heatand/or pressure. When in a softened state, the material is above itsglass transition (T_(g)) and may exhibit behavior similar to that of amolten material. The softened material is extruded into a film, and abobbin and/or housing are positioned such that their ends extend atleast partially into the film. The positioning may occur while the filmof thermoplastic elastomer is in the softened state. Alternatively, thebobbin and/or housing may be heated to a temperature that is greaterthan the temperature of the film before the bobbin and/or housing arepositioned in the film. The film with the bobbin and/or housing iscooled so that the thermoplastic elastomer is no longer softened butinstead is in a “rubber state” in which the thermoplastic elastomerexhibits rubber-like properties. During the transition from the softenedstate to the rubber state, the bobbin and/or housing is secured to thefilm.

Thermoplastic elastomers combine elastomeric properties with advantagesof thermoplastics and can typically be processed and shaped usingtechniques similar to those used for thermoplastics. In some instances,thermoplastic elastomers are block copolymers with elastomers and can beused as a replacement for vulcanized rubbers. Advantageously,thermoplastic elastomers have inherently high viscosity and, unliketechniques utilizing other types of elastomeric materials for formingcompliant members, no extended heating period is necessary for curing.Instead, the application of heat is limited to that appropriate to causethe material to flow as thermoplastic elastomers generally have highermelt viscosities than thermoset rubbers.

Some thermoplastic elastomers having a hardness from about 15 Shore A toabout 90 Shore A and therefore may be too stiff for obtaining asufficiently compliant member; however, other thermoplastic elastomers,such as oil extended thermoplastic elastomers, can be used. For example,thermoplastic elastomers having a hardness of less than 15 Shore Aand/or a Young's modulus of less than 0.25 MPa can be used.

By way of example, the thermoplastic elastomer may be a thermoplasticvulcanizate (TPV) such as Sarlink® from Teknor Apex Company, Pawtucket,R.I. In an alternative example, the thermoplastic elastomer may be astyrenic-based thermoplastic elastomer such as Medalist® MD-16120G orMedalist® MD-447 from Teknor Apex. In another example, the thermoplasticelastomer may be a derivative, such as an α-methyl styrene-basedthermoplastic elastomer.

FIG. 2 is a flowchart representation of an example of a method 100 offabricating a device having a compliant member. Reference is also madeto FIGS. 3A to 3C which are cross-sectional side view illustrationsshowing, in a sequential manner, the method 100 as applied tofabrication of a microspeaker device in which the compliant member cansubsequently be processed to form an acoustic diaphragm and a surround.

According to the method 100, heat is applied (110) to a thermoplasticelastomer (TPE) to achieve and maintain the thermoplastic elastomer in asoftened state. If a styrenic-based thermoplastic elastomer is used, theheat applied is sufficient to heat the thermoplastic elastomer greaterthan the glass transition temperature T_(g) of the styrenic component(e.g., greater than 100° C.) at which the material begins to soften. Ifa thermoplastic vulcanizate is used, the applied heat is sufficient toheat the material to a temperature greater than the crystalline meltingtemperature T_(m) of the polypropylene component (e.g., greater than160° C.).

Reference is also made to FIG. 4 which shows the storage modulus of anexample thermoplastic elastomer material (Medalist® MD-447 medicalelastomer) as a function of temperature. The material has asubstantially constant storage modulus value from below room temperatureto greater than 100° C. At higher temperatures, the storage modulusdecreases and the material transitions from a rubber state to a softenedstate with increasing temperature. The thermoplastic elastomer isextruded (120) to form a sheet or film on a release liner. For example,the thermoplastic material corresponding to FIG. 4 may be at atemperature of approximately 125° C. or greater during extrusion.

FIG. 3A is an example cross-sectional side view of a thermoplasticelastomer film 22 on a release liner 24. The thermoplastic elastomermaterial may be provided as a granulate (e.g., pellets) and fed by anextrusion screw under application of heat (e.g., increase temperature ofthermoplastic elastomer material to between 190° C. and 200° C.). Thesoftened thermoplastic elastomer is extruded through a die onto therelease liner 24. A housing and bobbin are then positioned (130) on thefilm 22 so that one end of each extends at least partially into the film22. For example, FIG. 3B shows a housing 28 and bobbin 30 (only endportions illustrated) with their ends extending at least partially intothe thermoplastic elastomer film 22. In one example, the housing 28 isin the form of a hollow cylindrical tube and the bobbin 30 is configuredto move in a bi-directional manner along the tube axis. The housing 28and bobbin 30 may be positioned at the same time. Alternatively, thehousing 28 and bobbin 30 may be positioned at different times as long asthe thermoplastic elastomer film 22 is in a softened state. Due to theinherently higher viscosity of a thermoplastic elastomer in a softenedstate relative to an uncured elastomeric material, the migration of thethermoplastic elastomer is substantially reduced relative that of theuncured elastomeric material. The reduction in material migrationresults in smaller menisci formed along the walls of the housing 28 andbobbin 30 as described further below. The thermoplastic elastomer film22 with the embedded housing 28 and bobbin 30 is then cooled (140) sothat the film 22 transitions to a rubber state and the housing 28 andbobbin 30 are secured to the film 22. Passive cooling may be used.Alternatively, active cooling can be employed to decrease themanufacturing time.

The release liner 24 is removed (150) so that the thermoplasticelastomer film 22 remains as a substantially planar compliant memberthat adheres to the end of the housing 28 and the bobbin 30 as shown inFIG. 3C. The central region of the compliant member, (i.e., the areadefined within the diameter of the bobbin 30) can be stiffened to formthe acoustic diaphragm. The annular area surrounding the central regiondefines a compliant surround that can support the bobbin 30 and coil,and enables the acoustic diaphragm to move axially to thereby generatean acoustic signal. The portion of the compliant member that extendsbeyond the outer diameter of the housing 28 may be removed (160) by anyof a variety of techniques such as by trimming or using a punch tool.

FIG. 5 shows a magnified cross-sectional view of a portion of the endsof the housing 28 and bobbin 30 corresponding to the left side of FIG.3C. A meniscus 32 is formed at locations where the thermoplasticelastomer film material has climbed (vertical migration in the figure)the walls of the housing 28 and bobbin 30. Thus, there is an innermeniscus 32A and an outer meniscus 32B along an inner wall surface 34and an outer wall surface 36, respectively, of the housing 28.Similarly, there is an inner meniscus 32C and an outer meniscus 32Dalong an inner wall surface 38 and an outer wall surface 40,respectively, of the bobbin 30. Each meniscus 32 has a height H₁ definedfrom the top surface 42 of the thermoplastic elastomer film 22. Themenisci 32 are formed during a period starting when the ends of thehousing 28 and bobbin 30 are first positioned in the softenedthermoplastic elastomer film 22. All menisci 32 are shown as having thesame height H₁; however, the heights along the two walls may differ dueto a difference in material migration along the walls according todifferences in the wall materials. The bottoms of the walls are notcoincident with the bottom of the thermoplastic elastomer film 22 asthere is some affinity between the thermoplastic elastomer material andthe wall regardless of the viscosity of the thermoplastic elastomerwhile in the softened state.

Due to the higher viscosity of the thermoplastic elastomer film 22 andthe corresponding reduction in material migration, the height H₁ of themenisci 32 is substantially less than a height H₂ of the menisci thatotherwise would have formed using an uncured elastomeric layer. As aresult, less thinning occurs and there is a substantial reduction inthickness variations across the thermoplastic elastomer film 22.Advantageously, the fabricated device is easier to remove from therelease liner (not shown) without tearing or generating holes. Moreover,the opportunity for holes or tears to be generated during operation of amicrospeaker device fabricated with the compliant member is reduced oreliminated. An additional advantage is a more consistent stiffness ofthe suspension defined by the peripheral portion of the compliant memberthat surrounds the inner acoustic diaphragm.

It should be noted that the elimination of the menisci 32 is not a goalas they represent an increased area of adherence to the walls of thehousing 28 and bobbin 30, and tearing can occur when the release lineris removed if no menisci are present. In addition, the menisci 32 limitthe stress concentration at the joint between the elastomer and thehousing and bobbin walls.

Reference is again made to U.S. patent application Ser. No. 15/182,069which discloses a two-pass film casting process for forming thecompliant member in which a second elastomeric layer is applied to athicker and at least partially cured first elastomeric layer. Theprocess achieves advantages over methods based on a single elastomericlayer; however, the methods described herein using a thermoplasticelastomer achieve additional advantages over the two-pass film castingtechnique due in part to the use of processes that can be implementedwith standard plastics processing equipment and readily-availablematerials. Moreover, a lower cost is realized by avoidance of curingprocesses and the related equipment costs, labor costs and manufacturingdelay. A further advantage of the examples of methods described hereinincludes low surface tack which eliminates the need for a specializedcoating on the release liner to facilitate separation from thethermoplastic elastomer film. Moreover, in contrast to thermosetelastomers, thermoplastic elastomer materials generally are not subjectto short expiration periods during which the materials must be used.

FIG. 6 is a flowchart representation of an alternative example of amethod 200 of fabricating a device having a compliant member. Accordingto the method 200, heat is applied (210) to a thermoplastic elastomer toachieve and maintain the thermoplastic elastomer in a softened state.The thermoplastic elastomer is extruded (220) to form a sheet or film ona release liner. The thermoplastic elastomer film and release liner arecooled (230) (e.g., passively cooled to ambient temperature) so that thethermoplastic elastomer film transitions to a rubber state. Optionally,the thermoplastic elastomer film and release liner may be wound on aroll or packaged in another configuration for convenient transport in asituation where subsequent fabrication is to occur at a differentlocation. The thermoplastic elastomer film and release liner are heated(240) so that the thermoplastic elastomer changes to a softened stateand the bobbin and housing are then positioned (250) in the softenedthermoplastic elastomer film. Subsequently, the thermoplastic elastomerfilm, release liner, bobbin and housing are cooled (260) to therebyreturn the film to a rubber state and secure the bobbin and housing tothe film. The release liner is then separated (270) from thethermoplastic elastomer film and the excess film, that is, the film thatextends beyond the diameter of the housing, is removed (280).

In one specific example, steps 210 through 230 are performed at onefacility where extrusion equipment is located and the resultingthermoplastic elastomer film and release liner are shipped to adifferent location where the remaining method steps are performed.

FIG. 7 is a flowchart representation of another example of a method 300of fabricating a device having a compliant member. Similar to theexamples described above, heat is applied (310) to change athermoplastic elastomer to a softened state and the softened material isextruded (320) to form a film on a release liner. The thermoplasticelastomer film and release liner are cooled (330) so that thethermoplastic elastomer film transitions to a rubber state. Unlike theprior method examples, the bobbin and housing are heated (340) to atemperature substantially greater than the temperature of thethermoplastic elastomer film before being positioned (350) in the film.For example, the bobbin and housing may be heated to a temperaturebetween approximately 190° C. and 210° C. The temperatures of the bobbinand housing are sufficiently high such that the thermoplastic materialin contact with and near to the bobbin and housing changes to a softenedstate due to conduction of thermal energy from the heated parts.Consequently, the bobbin and housing extend at least partially into thefilm. The bobbin and housing are then cooled (360), either actively orpassively, to secure them to the film. Subsequently, the release lineris separated (370) from the film and the film extending beyond the outerdiameter of the housing is removed (380).

A number of implementations have been described. Nevertheless, it willbe understood that the foregoing description is intended to illustrate,and not to limit, the scope of the inventive concepts which are definedby the scope of the claims. Other examples are within the scope of thefollowing claims.

What is claimed is:
 1. A method of fabricating a device having acompliant member, comprising: applying heat to a thermoplastic elastomerto maintain the thermoplastic elastomer in a softened state; extrudingthe thermoplastic elastomer in the softened state into a film ofthermoplastic elastomer; positioning one or more of a bobbin and ahousing, each having an end, such that the end of the bobbin and/orhousing extends at least partially into the film of thermoplasticelastomer, the positioning occurring when the thermoplastic elastomer isin the softened state and/or the bobbin and/or housing is at atemperature that is greater than a temperature of the film ofthermoplastic elastomer; and cooling the film of thermoplastic elastomerhaving the bobbin and/or housing positioned therein, wherein the bobbinand/or housing is thereby secured to the film of thermoplasticelastomer.
 2. The method of claim 1 wherein extruding the thermoplasticelastomer comprises extruding the thermoplastic elastomer as a film on arelease liner.
 3. The method of claim 2 further comprising removing therelease liner from the film of thermoplastic elastomer subsequent to thecooling of the film of thermoplastic elastomer.
 4. The method of claim 1wherein the film of thermoplastic elastomer is cooled into a rubberstate, the method further comprising applying heat to the film ofthermoplastic elastomer in the rubber state to change the film ofthermoplastic elastomer into the softened state prior to the positioningof the housing.
 5. The method of claim 1 wherein the temperature of thefilm of thermoplastic elastomer is at an ambient temperature when thehousing is at a temperature that is greater than the temperature of thefilm of thermoplastic elastomer.
 6. The method of claim 1 furthercomprising removing a portion of the film of thermoplastic elastomerthat extends outside a diameter of the housing after cooling the film ofthermoplastic elastomer.
 7. The method of claim 1 wherein thethermoplastic elastomer comprises a thermoplastic vulcanizate.
 8. Themethod of claim 1 wherein the thermoplastic elastomer comprises astyrenic-based thermoplastic elastomer.
 9. The method of claim 1 whereinthe thermoplastic elastomer has a hardness of less than 15 Shore A. 10.The method of claim 1 wherein the thermoplastic elastomer has a Young'smodulus of less than 0.25 megapascals.
 11. The method of claim 1 whereinpositioning one or more of a bobbin and a housing comprises positioningthe bobbin and the housing such that the bobbin is inside the housingand concentric with the housing.
 12. The method of claim 7 whereinapplying heat to the thermoplastic vulcanizate to maintain thethermoplastic vulcanizate in a softened state comprises heating thethermoplastic vulcanizate to greater than a crystalline meltingtemperature of a polypropylene component.
 13. The method of claim 8wherein applying heat to the styrenic-based thermoplastic elastomer tomaintain the styrenic-based thermoplastic elastomer in a softened statecomprises heating the styrenic-based thermoplastic elastomer to greaterthan a glass transition temperature of a styrenic component.
 14. Themethod of claim 1 wherein the bobbin and/or the housing is at atemperature that is in a range from about 100° C. to about 200° C.during the positioning of the bobbin and/or the housing.
 15. A devicecomprising: a compliant member having a substantially planar shape andformed of a film of a thermoplastic elastomer; and a housing having anend that extends at least partially into the compliant member, whereinthe thermoplastic elastomer adheres to a portion of the housing at theend of the housing to form a meniscus having a height defined along awall of the housing.
 16. The device of claim 15 further comprising abobbin disposed inside the housing and having an end that extends atleast partially into the compliant member, wherein the thermoplasticelastomer adheres to a portion of the bobbin at the end of the bobbin toform a meniscus having a height defined along a wall of the bobbin. 17.The device of claim 15 wherein the housing is a tube having an openingat the end.
 18. The device of claim 15 wherein the thermoplasticelastomer comprises a thermoplastic vulcanizate.
 19. The device of claim15 wherein the thermoplastic elastomer comprises a styrenic-basedthermoplastic elastomer.
 20. The device of claim 15 wherein thethermoplastic elastomer has a hardness of less than 15 Shore A.
 21. Thedevice of claim 15 wherein the thermoplastic elastomer has a Young'smodulus of less than 0.25 megapascals.
 22. The device of claim 15wherein the complaint member includes a meniscus formed at each of aninner wall surface of the housing and an outer wall surface of thehousing.
 23. The device of claim 16 wherein the compliant memberincludes a meniscus formed at each of an inner wall surface of thehousing, an outer wall surface of the housing, an inner wall surface ofthe bobbin and an outer wall surface of the bobbin.
 24. A microspeakerdevice comprising: an acoustic diaphragm having a substantially planarshape and formed of a film of thermoplastic elastomer; a housing havingan end extending at least partially into the film of thermoplasticelastomer, wherein the film adheres to a portion of the housing at theend of the housing to form a first meniscus along a portion of a wall ofthe housing; a bobbin having a bobbin surface and being disposed insidethe housing, the bobbin having an end extending at least partially intothe film of thermoplastic elastomer, wherein the film adheres to aportion of the bobbin at the end of the bobbin to form a second meniscusalong a wall of the bobbin; and a coil wound on the bobbin surface. 25.The microspeaker device of claim 24 wherein the first meniscus comprisesa first inner meniscus having a height along an inner wall surface ofthe housing and a first outer meniscus having a height along an outerwall surface of the housing and wherein the second meniscus comprises asecond inner meniscus having a height along an inner wall surface of thebobbin and a second outer meniscus having a height along an outer wallsurface of the bobbin.
 26. The microspeaker of claim 24 wherein an axisof the housing and an axis of the bobbin are colinear.